This invention relates to an ink fountain for printing machines in which the ink dispensing elements are pivotally mounted with respect to the fountain roller so as to provide an adjustment of the ink density across all of the printing zones.
Printing presses commonly employ an ink fountain in which ink is metered by a fountain blade having a precisely adjusted spacing with respect to the surface of a fountain roller. Details of the blade construction and adjusting means are provided, for example, in Cappel et al. U.S. Pat. No. 3,978,788 issued Sept. 7, 1976, herein incorporated by reference.
The ink trough in an ink fountain is defined by the surface of a fountain roller and by a sub-frame which, in some designs, is pivotally mounted to the sidewalls of the main frame of the printing press. In Cappel et al. U.S. Pat. No. 3,978,788, for example, the sub-frame is pivotally mounted so that end plates secured to the sub-frame may bear against respective ends of the sub-frame and respective ends of the fountain roller. The end plates, in other words, form the sides of the ink trough and provide sealing with respect to the fountain roller. In Simeth et al. U.S. Pat. No. 4,357,872, the sub-frame is pivotally mounted to the main frame and the pivot connection has an eccentricity so that the spacing between the blade and fountain roller may be periodically enlarged to promote the diversion of contaminated ink so as to prevent clogging.
In Hans Johne et al. U.S. Pat. No. 3,696,743 (corresponding to West German Pat. No. 1,942,732) the sub-frame of an ink fountain is pivotally and eccentrically mounted to provide means for adjusting the spacing between the blade and the fountain roller for all of the printing zones. This kind of mechanism is useful in color printing to adjust the relative densities of the primary colors.